Figure 4.

Genealogical diversity and the rate of adaptive evolution at different levels of coinfection when selection acts only on the antigenic gene segment. (A) Distribution of mean TMRCAs of the antigenic (red) and non-antigenic (blue) gene segments, obtained from 500 independent simulations for each model parameterization considered and calculated from over the last 20 years of each simulation. Three model parameterizations were considered, corresponding to different levels of coinfection: 0 per cent (β = 0), 5 per cent (β = 0.0125), and 9 per cent (β = 0.025). The dashed lines show the mean of the distributions. (B) Mean (log) fitness of the virus population over time under the three coinfection levels considered.